METHOD AND APPARATUS FOR WRAPPING

Abstract: A method for packaging bodies (1), primarily bales (1) of moist or wet animal-feed, by wrapping the body in a thin plastic film band (2), wherein a plastic web is wound onto the body in successive turns (3) while maintaining the web in tension. The web is taken from a magazine (4) while rotating the body about its longitudinal axis (5), which is preferably essentially horizontal, with the turns extending generally parallel with and transversely to the longitudinal axis, wherein wrapping of the body is terminated by gripping the web at a web part located between the magazine and the body, therewith severing the web. The method is mainly characterized in that the plastic web (2) is caused to extend transversely to the longitudinal axis (5) and herewith run from the magazine (4) essentially tangentially to the body (1) and transversely to the longitudinal axis, before the web is gripped at the web part located adjacent the body. This invention also relates to a body wrapping arrangement.

Description: Method and apparatus for wrapping The present invention relates to a method for packaging bodies, primarily moist or wet bales of cattle-feed, where- in a thin plastic web is wrapped around the body in succes¬ sive turns while maintaining the web in tension, wherein the plastic web is taken from a magazine while simulta¬ neously rotating the body around a preferably essentially horizontal longitudinal axis of the body, wherein said turns extend in a plane which includes essentially the aforesaid longitudinal axis, and wherein the wrapping process is terminated by gripping the plastic web at a web region between the magazine and the bale, such as to break the web. The invention also relates to an arrangement for carrying out the method. Methods of this general kind are known to the art. When wrapping bales of moist or wet horse-feed for storage in a bale silo, a bale is placed on a table with the longitudi¬ nal axis of the bale extending generally horizontally, and the bale is rotated about its longitudinal axis and the plastic web is wrapped around the bale in successive turns which essentially include the longitudinal axis of the bale, with the aid of rotators provided herefor, such as endless belts, and by rotating the table or swinging the film magazine at the same time. When wrapping of the bale is completed, the plastic web is gripped by means of a gripping device mounted on the table and the web is torn- off or severed in some other way. One serious problem is that a considerable length of plas¬ tic web is left dangling freely from the bale, which has serious drawbacks. These dangling lengths of plastic web cause substantial disturbances in the surroundings when flapping in the wind, and tend to fasten in the branches of trees etc. , and remain hanging from the bales for a long period of time. Furthermore, as a result of these loose ends film is unwound from the bales as the bales are han¬ dled, therewith exacerbating the aforedescribed problems and may cause the plastic sheet applied to the bale to lose some of its sealing effect. The present invention provides a simple and effective solu¬ tion to the aforesaid problems and enables the plastic film applied to be better utilized, among other things. The invention thus relates to a method according to the preamble of the following Claim 1, this method being char¬ acterized mainly by the features set forth in the charac¬ terizing clause of said claim. The invention also relates to an arrangement according to the preamble of the following Claim 7, said arrangement being characterized mainly by the features set forth in the characterizing clause of said apparatus claim. The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawing, in which Figure 1 illustrates schematically a first embodiment of an inventive arrangement as seen in the direction of the longitudinal axis of a body to be wrapped and in the width direction of the web of plastic film, wherein although the web is intended to be gripped it is shown in a free state, with the devices for gripping the plastic web shown in an inactive state; Figure 2 illustrates the arrangement of Figure 1 and shows web gripping means in an active gripping state; Figure 3 illustrates the web gripping devices of Figure 1 schematically and from the left in Figure 1; Figure 4 illustrates the web gripping devices of Figure 2 schematically and from the left in Figure 2; Figure 5 is a schematic vertical section view of the grip¬ ping devices shown in Figure 2; Figure 6 illustrates the gripping devices of Figure 2 schematically and from above in Figure 2; Figure 7 illustrates schematically an inventive device for activating and deactivating stretching of the plastic web; and Figure 8 illustrates schematically a further inventive device for activating and deactivating stretching of the plastic web. In Figure 1 the reference numeral identifies a body in the form of a bale of animal-feed which is to be wrapped in thin plastic film 2, which is intended to be applied in successive turns 3 from a magazine 4 or storage reel while rotating the body around its preferably horizontal longitu¬ dinal axis 5 and while, in the case of the illustrated embodiment, simultaneously turning the body on an axle 6 which extends generally at right angles to the axis 5, said body being placed on a table 7 which is rotatable about the axle 6 and which includes transporters or rotators 8, such as endless belts 8, for rotating the body around the axis 5. Although not shown, the magazine is positioned generally vertically in this regard. Devices (not shown) are provided for placing the magazine 4 in a preferably generally horizontal position, shown in Figures 1 and 2, wherein the magazine axis 9 extends gener¬ ally parallel to the long axis 5, and wherein the plastic web is intended to be wrapped around the body in successive turns 10 with the turns crossing earlier applied turns 3 along the outer surface of the body essentially parallel with the longitudinal axis thereof, as shown in Figure l. In the illustrated case, the plastic web moves circum- ferentially around the body transversely to the longitudi¬ nal axis 5, and enters from the magazine tangentially to the body and transversely to the longitudinal axis. The plastic web is preferably provided with an adhesive. The reference numeral 11 identifies gripping devices which are intended to grip the length of plastic web extending from the magazine to the body transversely to the longitu¬ dinal axis thereof at a web part which lies adjacent the body, as shown i Figure 2. In this regard, it is preferred that the plastic web runs into the body with its width direction essentially parallel with the longitudinal axis of said body and in beneath the body, wherein the gripping devices 11 are preferably disposed on the side 7 of the table 7 that extends parallel with said longitudinal axis, adjacent the transporters 8. According to one preferred embodiment, the gripping devices 11 include two mutually opposing arms 12 or like devices which preferably extend essentially parallel with the longitudinal axis 5 in their active and inactive positions. The arms 12 are arranged to be moved-in over the plastic web extending transversely to the longitudinal axis, from respective longitudinally extending edge-part 13 of the web and to act against an anvil surface or counter-pressure surface 14 provided adjacent the body, as indicated in Figures 2 and 4. As the body is being wrapped, the arms 12 are held extended outwardly, away from each other, and preferably essentially parallel with the longitudinal axis 5. According to one embodiment which is preferred in some cases, each of the arms is extended by means of a respec¬ tive chain wheel 15 or corresponding wheel-like or roller¬ like device. Extending between the chain wheels 15 is a spring-loaded chain 15' or like movement transmitting means which coacts with the devices 15 and extends in a loop to a pulling device 16, such as a hydraulic piston-cylinder device or the like, so as to enable the devices 15 to be rotated in opposite directions and therewith respectively extend and fold the arms in towards and out away from each another and the anvil surface 14. According to another embodiment of the gripping devices, the plastic web is intended to be gripped and firmly clamped by means of an arm which preferably extends gener¬ ally parallel with said longitudinal axis in an active and an inactive state and which when gripping the web gathers the web together slightly and is extended over the plastic web from a position in which it is at least slightly be¬ neath the plastic web and therewith act against an anvil surface mounted adjacent the body. During a wrapping opera¬ tion, when in its inactive position the arm extends in a direction away from the plastic web, preferably generally parallel with the longitudinal axis 5. The reference numeral 18 identifies tool parts which are disposed between the body and said arm/arms in a row along the anvil surface and preferably parallel with the arm/arms in mutually spaced relationship, these tool parts being intended to pierce through the plastic web as the web is gripped and therewith assist in tearing-off the web. According to one preferred embodiment of the invention, the plastic web, which is drawn-off from the magazine, is in¬ tended to be stretched in a known manner as it is drawn from the magazine by means of a stretching roller 19 which rotates at a higher peripheral speed than the magazine reel, wherein the plastic web runs from the magazine via the web stretching roller, and wherein rotary movement of the roller is transmitted to a braking roller 20 which rolls against the magazine reel, as shown schematically in Figures 7 and 8. In accordance with the invention, the apparatus includes devices 21, shown schematically in the drawing, which function to cause stretching of the web to cease generally, so as to reduce generally the force re- quired in the plastic web to pull the web from the storage reel, among other things in order to avoid the web slipping from the gripping devices when severing/pulling the web and starting a new body wrapping operation. As schematically illustrated, the devices 21 may have the form of devices (not shown) which function to disengage the braking roller from the web stretching roller and/or which function to lift the braking roller out of engagement with the storage reel, as indicated schematically by an arrow 21, wherein the storage reel will rotate at the same peripheral speed as the web stretching roller in both instances, the stret¬ ching roller otherwise rotating at a peripheral speed which is about 70% higher than the peripheral speed of the stor¬ age reel. The devices 21 for engaging and disengaging the braking roller may alternatively have the form of belt discs 22, 23 mounted adjacent the rollers 19 and 20 respec¬ tively, and a belt 24, for instance a four-slot V-profiled belt, which extends in tension between the belt discs 22, as shown in Figure 8, and which transmits movement between the rollers but which when not in tension slips and disen¬ gages the braking roller 20. In the illustrated case, the belt is held tensioned by a spring-loaded tensioning roller 25 and is brought to a relaxed state by means of a pressing hydraulic piston-cylinder device 26 for instance, as illus- trated in Figure 8. The braking roller is preferably spring biased so that as the storage reel becomes depleted of plastic film the roller will adjust to the varying diameter of the reel in a radial direction, wherein the braking roller is arranged to be moved out of contact with the storage reel through a predetermined, preferably short distance which is generally independent of the diameter of the storage reel. When appropriate, lifting devices, such as a hydraulic piston- cylinder device, may also be arranged to accompany the varying diameter of the storage reel in some suitable way, for instance with the aid of an attachment whose position also varies. The method and the manner in which the inventive apparatus works will be understood in all essentials from the afore¬ going. After being wrapped around the body in successive turns in a plane which essentially includes said longitudinal axis, the web is caused to pass transversely to the longitudinal axis and to run out towards the storage reel adjacent the rotators and to be gripped in this position at a location adjacent the body and torn-off or otherwise severed by rotation of the body around said longitudinal axis and, when applicable, the free end of the web is fastened to the body upon continued rotation thereof. The two gripping arms are constructed so as to enable the arms to be extended away from one another as the plastic web is wrapped around the body, and are not brought into gripping engagement with the web until the web is positioned above the anvil sur¬ face. This applies in the case of a single arm. After removing the wrapped or packaged body, a new body is placed in position while the plastic web running from the storage reel is held gripped by means of the gripping devices, whereafter wrapping of the new body is commenced. In conjunction with terminating the wrapping of one body and commencing the wrapping of a new body, the tension in the web may be relaxed so that less force is required to pull the web from the storage reel, therewith eliminating the risk of the web loosening from the gripping devices. It will be apparent from the aforegoing that the invention affords considerable advantages over the known technique. The plastic web is severed close to the body and the free end of the web can be wound onto the body transversely to the longitudinal axis and there secured. This eliminates the problem of long loose ends dangling from the wrapped bodies while affording functional severing of the web and functional termination and commencement of body wrapping operations. The turns that are wrapped in the circum¬ ferential direction of the body, and which are applied while maintaining the plastic web under tension, assist in holding the underlying turns of the web in tight and close relationship, therewith utilizing the plastic web more effectively and enabling the underlying wrapping to be reduced to a corresponding extent while retaining the func¬ tion of the wrapping as a whole. The ability to tension and to relax the plastic web pro¬ vides a high degree of reliability in operation, thereby avoiding production shortfalls as a result of interrupted wrapping operations and the refastening of the plastic web by an operator, who often works alone and is often seated in a vehicle located at some distance from the wrapping station concerned. Although the invention has been described with reference to exemplifying embodiments thereof it will be understood that other embodiments and minor changes and modifications are conceivable without departing from the concept of the in¬ vention. The invention can also be applied, of course, with methods and apparatus in which the magazine, or storage reel, can be swung around the body on an arm or like de- vice, in which case a body is wrapped by rotating the body about its longitudinal axis and swinging the magazine around the bale before bringing the plastic web finally to a position in which the web is severed and fastened in accordance with the invention. It will also be understood that the invention can be ap¬ plied both to generally cylindrical bales and to generally parallelepipedic bales. The invention is therefore not restricted to the afore- described and illustrated exemplifying embodiments thereof, since modifications can be made within the scope of the following claims.

Claims: CLAIMS 1. A body packaging method, primarily for packaging bales of moist or wet animal-feed, by wrapping the body in a thin web of plastic film, wherein a plastic web is taken from a magazine and wrapped around the body in successive turns while maintaining the web in tension and while rotating the body about its preferably generally horizontal longitudinal axis, wherein said turns run generally parallel with and transversely to said longitudinal axis, and wherein wrap¬ ping of the body is terminated by gripping the plastic web at a part thereof located between the magazine and the body, such as to break the web, characterized by causing the plastic web (2) to run transversely to said longitudi- nal axis (5) and herewith extend from the magazine (4) essentially tangentially to the body (1) and transversely to the longitudinal axis prior to gripping the web at a web part which lies adjacent the body. 2. A method according to Claim 1, characterized by causing the plastic web to move in to the body and gripping the web with the width direction of said web extending generally parallel with said longitudinal axis. 3. A method according to Claim 1 or 2, characterized by gripping and clamping the web by means of two arms (12) which extend preferably generally parallel with said longi¬ tudinal axis, said arms being extended grippingly across the plastic web from respective long sides (13) thereof and acting against an anvil surface (14) mounted adjacent the body. 4. A method according to Claim 1, 2 or 3, characterized by severing the web at its gripped position by rotating the body about its longitudinal axis, therewith drawing the plastic web in beneath said body. 5. A method according to Claim 1, 2 , 3 or 4, in which the plastic web is stretched by means of a web stretching roller (19) which rotates at a higher peripheral speed than the magazine reel, and in which the rotary movement of the web stretching or tensioning roller is transmitted to a braking roller (20) which rolls on the magazine reel, characterized by causing tensioning of the web to cease generally, so as to essentially reduce the force required to withdraw the web from the magazine reel. 6. A method according to Claim 5, characterized by ceasing to tension the web as wrapping of a body is commenced. 7. A body packaging arrangement, primarily for packaging bales of moist or wet animal-feed, by wrapping said body in thin plastic film, said arrangement comprising devices for applying to the body a plastic web, taken from a magazine, in successive turns while maintaining the web in tension during rotation of the body about a preferably generally horizontal longitudinal axis thereof, wherein said turns extend generally parallel with and transversely to said longitudinal axis, and wherein the arrangement further in¬ cludes devices for gripping the plastic web at a part thereof located between the body and the magazine, and devices for severing the web upon completion of a body wrapping operation, characterized in that the arrangement further includes devices (4) which function to cause the plastic web (2) to extend transversely to said longitudinal axis (5) and to run into said body essentially tangentially and transversely to the longitudinal axis and to grip the web in this position at a web part located adjacent said body. 8. Arrangement according to Claim 7, characterized by devices (4, 11) for causing the plastic web to move into the body and be gripped with the width direction of the web essentially parallel with said longitudinal axis. 9. An arrangement according to Claim 7 or 8, characterized by two arms (12) which preferably extend essentially paral¬ lel with said longitudinal axis and which function to grip and clamp the plastic web and which are intended to be extended grippingly over the plastic web from respective long sides (13) thereof and to act against an anvil surface (14) mounted adjacent the body. 10. An arrangement according to Claim 9, characterized in that during a wrapping operation the arms (12) are extended outwardly away from one another and are preferably general¬ ly parallel with said longitudinal axis. 11. An arrangement according to Claim 7 or 8, characterized in that the plastic web is gripped and clamped by means of an arm which preferably extends generally parallel with said longitudinal axis and which is intended to gather the web together slightly when gripping said web, and which is extended over the plastic web from a position in which it is located at least partially beneath said web and there¬ with act against an anvil surface mounted adjacent the body. 13. An arrangement according to Claim 9, 10 or 11, charac- terized by a row of mutually spaced tool parts (18) dis¬ posed between the body and the gripping devices (11) and intended to pierce through the plastic web so as to facili¬ tate severing of said web. 13. An arrangement according to Claim 7, 8, 9, 10, 11 or 12. which includes a body laying-off table (7) comprising a rotator (8) which functions to rotate the body about said longitudinal axis, characterized in that the gripping devices (11) are disposed adjacent said rotator (8) on that side (7) of the table extending parallel with said longitu¬ dinal axis. 14. An arrangement according to Claim 9 or 10, character¬ ized in that each of the arms (12) is extended by means of a respective chain wheel (15) or the like and a spring- loaded chain (15') or the like which extends in a loop between said chain wheels (15) to a pulling device (6), such that opposite rotation of the wheels will result in extension of the arms towards and away from each other and towards and away from said anvil surface (14). 15. An arrangement according to Claim 7, 8, 9, 10, 11, 12, 13 or 14, which includes web tensioning or stretching devices located adjacent the magazine and further includes a web tensioning roller which rotates at a higher peripher¬ al speed than the magazine reel, and which further includes devices for transmitting the rotary movement of the ten¬ sioning roller to a braking roller which rolls against the magazine reel, characterized by devices (21) which function to cause tensioning of the web to cease essentially so as to generally reduce the force required to pull the plastic web from the storage reel. 16. An arrangement according to Claim 15, characterized in that transmission of the rotary movement of the web ten¬ sioning roller (19) to the braking roller (20) can be disengaged. 17. An arrangement according to Claim 15 or 16, character¬ ized by devices (21) for lifting the braking roller (20) out of contact with the magazine reel (4).

Inventors: SOEDERBERG STAFFAN, SOEDERBERG, STAFFAN
Applicants: SOEDERBERG STAFFAN, SOEDERBERG, STAFFAN
Application year: 1994
Main classification: B65B11
IPC codes: A01F15, B65B11